Date

/**
* Date类型转换成Long型日期
* 
* @param date
* @return
*/
public static Long toLongDate(Date date) {
if (date == null) {
return null;
}
return Long.valueOf(new SimpleDateFormat(LONG_DATE_FMT).format(date));
}

      

/**
* 把日期的时分秒去除只留年月日
* 
* @param date
* @return 只留年月日的日期
*/
public static Date clearTime(Date date) {
if (date == null) {
return null;
}

Calendar calendar = getCalendar();
calendar.setTime(date);
int y = calendar.get(Calendar.YEAR);
int m = calendar.get(Calendar.MONTH);
int d = calendar.get(Calendar.DAY_OF_MONTH);
calendar.clear();
calendar.set(Calendar.YEAR, y);
calendar.set(Calendar.MONTH, m);
calendar.set(Calendar.DAY_OF_MONTH, d);
return calendar.getTime();
}

/**
* 日期转化为字串
* 
* @param date
* @param pattern
* @return
*/
public static String dateToStr(Date date, String pattern) {
if (date == null || pattern == null) {
return null;
}

SimpleDateFormat sdf = new SimpleDateFormat(pattern);
return sdf.format(date);
}